Persistent access control of protected content

A method for providing content protection on a client information processing system, comprising the steps of:

• acquiring on the client information processing system a file comprising content encrypted with a first encrypting key and a trailer related to the content;
• determining whether a connection to a server information processing system for access to the content is available;
• wherein if the connection to the server information processing system is not available,
• determining if authorization for access to the content is cached in the client information processing system;
• and
• wherein if authorization for access to the content is cached in the client information processing system, accessing the content in the file using a client application.

A method on a server information processing system for providing authorization for access to content, comprising the steps of:

• receiving a first request from a client information processing system for authentication of the client information processing system;
• wherein if the first request of the client information processing system meets authentication requirements,
• sending a reply to the first request to client information processing system, wherein the reply includes an authentication of the client information processing system;
• receiving a second request from the client information processing system for access to content in a file including a trailer, wherein the second request includes an identifier from the trailer associated with the content;
• determining whether the second request is in accordance with an access control policy associated with the content;
• and
• wherein if the second request is in accordance with an access control policy associated with the content, sending a reply to the second request to the client information processing system, wherein the reply includes a grant of access to the content to the client information processing system.

A computer readable medium including computer instructions for providing content protection on a client information processing system, the computer instructions providing instructions for:

• sending a first request to a server information processing system for authentication of the client information processing system;
• wherein if the client information processing system is authenticated by the server information processing system,
• receiving a reply to the first request from the server information processing system, wherein the reply includes an authentication from the server information processing system;
• sending a second request to the server information processing system for access to a file using a client application, wherein the file comprises content encrypted with a first encrypting key and a trailer associated with the content and wherein the second request includes an identifier from the trailer;
• wherein if the server information processing system determines that the second request is in accordance with an access control policy associated with the content,
• receiving a reply to the second request from the server information processing system, wherein the reply includes a grant of access to the content;
• and
• accessing the content in the file using the client application.

A system on a client information processing system for providing content protection, comprising:

• a file comprising content encrypted with a first encrypting key and a trailer related to the content;
• a first request to a server information processing system for authentication of the client information processing system;
• a reply to the first request from the server information processing system, wherein the reply includes an authentication from the server information processing system;
• a second request to the server information processing system for access to the content, wherein the second request includes an identifier from the trailer associated with the content;
• and
• a reply to the second request from the server information processing system, wherein the reply includes a grant of access to the content.

A system on a server information processing system for providing authorization for access to content, comprising:

• a first request from a client information processing system for authentication of the client information processing system;
• a reply to the first request to client information processing system, wherein the reply includes an authentication of the client information processing system;
• a second request from the client information processing system for access to content in a file including a trailer, wherein the second request includes an identifier from the trailer associated with the content;
• and
• a reply to the second request to the client information processing system, wherein the reply includes a grant of access to the content to the client information processing system.